Thermostatically-regulated incubator



May 10, 1927.

J; v. GI ESLER' THERMOSTATICALLY REGULATED INCUBATOR Filed June 16, 19242 Sheets-Sheet l May 10, 1927.

J. V. GIESLER THERMOSTATICALLY REGULATED INCUBATOR 2 Sheets-Shet 2 FiledJune 16, I924 present invention,

Patented May 10, 1927.

UNITED STATES PATENT OFFICE.

' JEAN v. GIESLER, or. KNOXVILLE, "TENNESSEE, ASSIGNOR 'ro THE FULTONCOMPANY, or KNOXVILLE, 'rnNNnssEn, A CORPORATION or MAINE.

THERMOSTATICALLY-REGULATED INCUBATOR.

Application filed June 16, 1924. Serial No. 720,434.

This invention relates to thermostatically controlled devices, and moreparticularly to devices of this character for use in regulating thetemperature of incubators.

Many different constructions have heretofore been proposed formaintaining anniform temperature in incubators, but devices of thischaracter heretofore proposed have been open to more or less numerousand se rious objections including lack of'accuracy and sensitiveness ofcdutrol, lack of facility in assembl and adjustment to enable them to bereadily set up and adjusted by unskilled persons, lack of simplicity andeconomy in construction and operation, etc.

1 It is an object of this invention to provide an incubator withthermostatic mechanism for regulating the temperature of the same whichis sensitive and accurate in the maintenance of predeterminedtemperatures, which is easy to assemble and install so that theincubator may be readily put together and all necessary adjustmentseasily made by unskilled persons, and which is simple and economical inconstruction and operation so that it is inexpensive to manufacture andeconomical in service.

The invention is capable of receiving a variety of'mechanicalexpressions, one of which, for purposes of illustration, has been shownon the accompanying drawings, but it is to be expressly understood thatthe drawings are for purposes of illustration only and are not to beconstrued as a definition of the limits of the invention, referencebeing had to the appended claims for that pur ose.

Referrlng in detail to the drawings, wherein the same referencecharacters are employed in different views to designate correspondingparts Fig. 1 is a more or less schematic sectional view illustrating theconstruction and arrangement of an incubator embodying the ortions beingbroken away for clearnes's oFillustration;

Fig. 2 is an enlarged axial view of the thermostatically operated valvein the water system; and

Fig. 3 is an enlarged fragmentary view showing the air thermostat andits mounting in axial section.

In the form shown, 10 designates the incubator casing, which ma be ofany suitable size and material and 0 any suitable manner'ofconstruction. Within saidincubator casing are disposed'means for heatingthe same, said means preferably taking the form of one or more coilsofpipe 11 through which is circulated a suitable heating medium, such ashot Water, said coil or coils having inlet connections 12 and outletconnectlons 13 which extend through the wall of the incubator andcommunicate with a heater 14 at the outside of the incubator.Circulation of the water to and from said heater and through the coil orcoils may be effected by a pump, or reliance may be placed upon thethermo-siphon system of circulation.

The'heater14 may be of any suitable construction. The' form shown is ofthe t pe adapted to be used in conjunction witi a lamp or any othersuitable type of burner, and includes an exterior casing 15 of anysuitable size, shape and material, an interior annular water tank havinginner and outer walls 16 and 17 and also of any suitable size, shape andmaterial, and within said tank an interior flue or chimney 18 which isopen at the bottom. Said flue 18 has a smaller diameter than the innerwall 16 of the water tank, while the outer wall 17 of said tank is ofless diameter than the diameter of the outer casin 15; hence annularpassages 19 and 20 are ormed between the inner flue 18 and the watertank and between the water tank and the outer casing, these passages 19and 20 constitutin the flue or chimney 18 reverse flues w ereby heatedair may be caused to circulate around the entire interior and exteriorsurfaces of the water tank. Communicating with the water "tank is anexpansion tank 21 of any suitable size adapted to provide for changes ofvolume of the water in the. circulating system upon changes oftemperature and also to make up for any evaporation or other loss ofwater.

In order to regulate the extent to which the heated air or gases passingup the flue or chimney 18 is made to circulate around the water tank toimpart heat thereto, and therefore to regulate the extent to which thewater is heated, the top of the heater is provided with an opening 22which may be made of the same diameter as that of the inner wall 16 ofthe water tank. Cooperating with said aperture 22 is a valve 23 whichmay take the form of a flat disk corwith responding in shape and size tothe aperture 22 and adapted to rest on the top of the heater so as toclose saidaperture and cause all of the hot air and gases which rise inthe flue or chimney 18 to pass laterally through the space between thetop of said flue or chimney 18 and said valve 23, and thence downwardlythrough the flue 19, through the space between the bottom of the watertank and the bottom of the casing 15, and up through the flue 20, whencethe hot air and gases may escape through the aperture 24 provided in thetop of the casing.

Valve 23 is preferably operated by a thermo stat and said thermostat ispreferably subjected to the temperature of the heated water. In the formshown a T connection 25 is interposed in the upper water line adjacentthe outlet from the heater and receives a thermostat 26 of any suitableconstruction mounted within the lateral aperture of said T connection sothat its bulb 27 is subjected to the temperature of the water in theupper water line. The operating stem 28 of said thermostat has a knifeedge or point engagement with a rocker 2!) mounted on a knife edgefulcrum 30 in a bracket or brackets 31 extending upwardly from thecasing of said thermostat. Rocker 29 is provided with an invertedstirrup 32 through which extends a bar or red 33 suitably held inadjusted position in said stirrup 32 by a set screw 34. Said bar or red33 is connected to the valve 23 at its opposite end by a chain or othersuitable element 35, and constitutes with said rocker 29 a lever bywhich said valve is operated as the thermostat expands and contracts. Toadjust the temperature at which the valve 23 is operated by thethermostat 26 one or more adjustable weights 36 are slidably mounted onthe bar or red 33 and retained in adjusted position by any suitablemeans as a set- .screw 37.

As the thermostat 26 is subjected to the temperature of the water in theupper water line adjacent the outlet from the heater, there will alwaysbe more or less circulation of water around the bulb 27 of thethermostat so that said thermostat will respond substantially to thetemperature of the water in the upper part of the heater. As thetemperature of the water rises, the thermostat, which is preferably ofthe type employing volatile liquid, will remain inactive owing to theresistance to expansion of the thermostat provided by the leverage ofthe weight 36. When the predetermined temperature at which thethermostat is'to begin operation is reached, however, the volatileliquid in said thermostat will by vaporization cause an expansion of thethermostat, raising the operating stem 28 to tilt the rocker 29 and itsbar or red 33 around the fulcrum 30 of said rocker. Thereby the valve 23willbe lifted from the to of the heater to open the aperture 22 anpermit some of the hot air and gases to escape through said aperturewithout passing through the reverse lines 19 and 20. As the temperatureof the water continues to rise, the thermostat will expand to a greaterextent, raising the valve 23 to a higher position and permitting more ofthe hot air and gases to escape from the heater without passing throughthe reverse flues 19 and 20. Continued expansion will result in thevalve 23 being eventually raised to a point wherein all of the hot airand gases will escape through the aperture 22 without exertingsubstantially any heating eflect on the water in the tank 14. Hence thetemperature of the water is accurately and sensitively controlled fromthe temperature of the water it elf and the desired temperature may beclosely maintained by adjustin the weight 36 on the bar or rod 33 topredetermine the time and extent of operation of the valve 23 by saidthermostat.

in addition to the heretofore described means for regulating theten'iperaturc of the water, means are also provided for regulating thetemperature of the air within the incubator casing. Tothis end the upperwater line is also provided, intermediate the thermostat 26 and thecasing wall, with a valve casing 40 of any suitable construction andprovided interiorly in any suitable way with a valve port 41.Cooperating with said valve port is a valve member 42 of specialconstruction which is more particularly shown in Fig. 2. Said valvemember at its upper portion is formed as the seg ment of a sphere so asto provide a spherical surface 43 which will contact the valve seat 44.at a relatively flat angle and thereby prevent sticking of the valvemember to its seat. Below said spherical portion 4:3, the valve memberis provided with a conical extension 45 which by its cooperation withthe valve port forms an annular passage that varies in area with theextent to which the valve member is lifted from its seat. Thereby theflow of heating medium through the valve port can be nicely graduated asrelatively large movements of the valve member can be produced withoutentirely opening the valve port. This enables a clo'er regulation of theextent of circulation of the heating medium, because in the case of adisk valve a movement of the valve member equal to one-fourth of thediameter of the port entirely opens said port so that all control of thequantity of heating medium must be efiected within a valve movement notexceeding one-fourth of the diameter of the port. With the presentinvention, however, the controlling action of the valve may be prolongedto any desired extent and the degree of increased circulationcorrespondill) ing to predetermined movements can be nicely andaccurately regulated.

Valve member 42 is carried and operated by a valve stem 46, and in orderto prevent the frictional opposition to movement of the valve whichexists when a packing gland'is employed, the valve housing.

is so constructed as to eliminate the necessity for such a gland. Asshown, the valve housing is provided with an elongated upwardlyextending portion 47 closed at its upper end by a centrally aperturedplug 48, the height of said extension 47 being such that the water inthe system may never reach the aperture 49 in said plug 48. The valvestem 46 extends loosely through said aperture 49 and in the form shownis threaded at its upper end to receive a clcvis 50 which is connectedto a baror rod 51 by means of a pin 52.

To operate the valve 42 a thermostat of any suitable type andconstruction is mounted within the incubator casing at such a point thatit will respond accurately and sensitively to the changes. oftemperature within the casing. In the form shown, the thermostat 53 iscomposed of a deeply corrugated expansible and collapsible tubular wall54, preferably of resilient metal, and closed at its opposite ends byrigid end walls 55 and 56. If desired, said thermostat may be providedwith an interior tubular stop as shown at 57 to limit the collapse ofthe thermostat and hence the opening of the valve when the thermostat iscold, and a filling opening suitably sealed is shown at 58. Thisthermostat is also preferably of the volatile fluid type so that theexpansion and contraction is effected bv changes in the vapor tension ofa suitable liquid contained therein.

While, as respects certain features of this invention, said thermostatmay be mounted in any suitable way the preferred construction, whichpossesses certain advantages as hereinafter pointed out, includes asleeve 59 which extends through the wall of the incubator casing and ist readed at its lower end as shown at 60. A washer 61 and a lock nut 62are provided on said lower end for clamping said sleeve fixedly inposition by engagement-with the inner surface'of the casing wall. Theprojection end of sleeve 59 constitutes a thermostat support andprovides for axial and rotatable adjustment of the thermostat. To thisend a plate 63 is provided with a centrally arranged and interiorlythreaded ann'ular extension 64 which is adapted to be threaded on to thelower end of said sleeve 59. Depending from said plate 63 is a suitablespider 65 having an inwardly directed ledge or shoulders on which thestationary end wall 55 of the thermostat 53 may rest. By rotating theplate 63 with the thermostat carried thereby upon the threaded end 60 ofthe sleeve 59, the thermostat may be raised or lowered with respect tosaid sleeve 59 and then locked in adjusted position by a lock nut 66. Bythis adjustment the location of the valve 42 with respect to its seatcan be determined when the thermostat is cold wit-h its head 56contracted againstthe stop 57.

The bore of the sleeve 59 also constitutes end and received within thesocket 68 pro vided by an elongated annular boss 69 on the movable endwall 56 of the thermostat 53. The opposite end of the rod 67 is providedwith a knife edge or pointed and is received within a notch in a rocker70 which is fulcrumed b means of knife edges 71 upon a bracket 7 2extending upwardly from 'a plate 7 3. Plate 73 is preferably providedwith an aperture and fits over the upwardly projecting end of the sleeve59 so that it may be rotated around said. upwardly projecting end forpurposes of adjusment to the end that the connections from the stem 67to the valve stem 46 may be properly tutes with said rocker 70 a leverfulcrumed at 71 for transmitting movement from the thermostat stem 67 tothe valve stem 46. said bar or rod 51 is preferably provided on thethermostat side of the fulcrum 71 with one or more slidably mountedweights 77 which may be retained in adjusted position in any suitableway as by set screws 78. Said weights are preferably so shaped that thecenter of gravity of the lever with 1tsweights is above the plane of thefulcrum 71 so that the'movement of the lever is accompanied by a shiftof the center of gravity in the same direction as the thermostat tendsto move the valve. This arrangement possesses the advantage that thechange in position of the center of gravity tends to compensate for thechange in resistance to expansion of the thermostat 53 offered by theresiliency of its lateral wall. 54. The dispositon of said weight 77 onthe opposite side of the stem 67 from the fulcrum 71 causes said weightsto maintain the knife edges of said fulcrum in operative position,because tending to tilt the rocker aligned. This fulcrum member 72, 73may I about the upper end of the stem 67 as an axis. The opposite end ofthe bar or lever 51 is preferably provided with a lighter weight 79which may be moved longitudinally of the bar or rod 51 to nicelypredetermine the temperature at which the thermostat 53 starts to openthe valve 42. To retain weight 79 in its adjusted position the uppersurface of the bar or rod 51 is preferably serrated as shown at and theslot through said weight 79 may be provided with a tooth for engagementin the serrations 80.

This manner of mounting the thermostat and its operating connections tothe valve member provides for ready adjustments that can be easily madeby unskilled persons. The fulcrum member 72, 73 may be readily broughtinto line so that the bar or rod 51 will extend at right angles from itsfulcrum to the point of attachment of the valve stem 46, and may befixedly clamped in its adjusted position by the lock nut 7t or othersuitable head on the sleeve 59. During such adjustments the fulcrummember, rotating around the tube 59, moves about the axis of theconnections from the thermostat to the lever and, owing to the pointcontact between the stem 67 and the thermostat wall 56, such adjustmentsmay be effected with-v out disturbing said connections. Similarly thethermostat 53 may be rotatably and axially adjusted by threading thesupport 63 on to or off of the inwardly projecting end of the sleeve 59,and then be fixedly clamped in adjusted position by the lock nut 66.During such adjustments the thermostat is also moving about the axis ofthe connections therefrom to the lever 70, 51 and owing to the point ofcontact between the stem 67 and the thermostat wall 56 these adjustmentsmay be effected without rotating or otherwise disturbing saidconnections. At the same time the connections between the thermostat andthe lever are securely held against accidental displacements owing tothe length of engagement between the stem 67 and the wall of the socket68. The form of the connection of the bar or rod 51 to the valve member42 is such that the valve stem 46 need not extend exactly in the axis.of the valve port, the spherical surface of engagement of the valvemember with the valve seat permitting considerable variation in thecontact of the member with its seat without danger of leakage and thefree passage of the valve stem through the aperture 49 insuring againstthe sticking of said stem if the latter be somewhat out of alignment.Moreover, the connections between the thermostat and the valve and theirmanner of mounting are such that substantially no frictional oppositionto movement exists, while the character of these connections is such asto facilitate expansion and contraction of the thermostat and thereforea nicer and more accurate control of the valve. At the sametime theweights provide an adjustment whereby the temperature at which thethermostat will respond to operate the valve may be nicely regulatedwithin very close limits.

It will therefore be perceived that an incubator has been provided withthermostatic mechanism whereby the temperature of the water is closelyand accurately maintained at a predetermined temperature and the extentof circulation of this water of predetermined temperature is accuratelyand closely regulated from the temperature of the air within theincubator casing. At the same time the provisions for adjustment tomaintain this nicely regulated temperature are simple and easilymanipulated so that necessary adjustments may be readily effected byunskilled persons. The entire structure is also free of complexities sothat it may be readily assembled and installed by unskilled persons,while the character of its component parts is such as to facilitateeconomical manufacture and operation.

While the embodiment of the invention illustrated on the drawings hasbeen described with considerable particularity, it is to be expresslyunderstood that the invention is not restricted thereto as the same iscapable of receiving a variety of mechanical expressions, some of. whichwill now readily suggest themselves to those skilled in the art, whilechanges may be made in the details of construction, arrangement andproportion of parts, and certain features used} without other features,without departing from the spirit of this invention. Reference istherefore to be had to the appended claims for a definition of thelimits of the invention.

What I claim is 1. In an incubator, in combination with the incubatorcasing, means for regulating the temperature within said casingincluding a valve and a lever for operating the same, a sleeveprojecting through the casing wall, an adjustable fulcrum plate for saidlever clamped in position by said sleeve, a thermostat adjustablymounted on the inner end of said sleeve, and a rod projecting freelythrough said sleeve and'contacting the movable wall of said thermostatand said lever. 2. In an incubator, in combination with the incubatorcasing, means for regulating the temperaturewithin said casing includinga valve and a lever for operating the same, a sleeve projecting throughthe casing wall, a thermostat rotatably adjustable about the axis ofsaid sleeve, a fulcrum plate for said lever rotatably adjustable aboutthe axis of said sleeve, and an operative connection having contactengagement with said thermostat and said lever extending in the axis ofsaid sleeve.

3. In an incubator, in combination with the incubator casing, means forcirculating water through said casing, a valve and a thermostatsubjected to the temperature within said casing for controlling thecirculation of water, a heater for said water outside of said casingincluding an upwardly extending flue for the passage of hot air withoutcontact with the heating surface and reverse'flues adjacent .the heatingsurface communicating with said firstnamed flue, a valve for determiningwhether or not the hot air shall traverse said reverse fiues, and athermostat subjected to the temperature ofthe water for operating saidlast-named valve.

4. In an incubator, in combination with the incubator casing, means forregulating the temperature within said casing including a watercirculation system, a valve in saidsystem and a lever for operating thesame, a sleeve projecting through said casing, a thermostat adjustablymounted on the inner end thereof, a member operatively connecting saidthermostat and lever passing through said sleeve, an adjustable fulcrummember for said lever clamped in adjusted position by said sleeve, asecond thermostat in said circulating system, a heater for said water,and controlling means therefor having .operative connection with saidsecond thermostat.

5. In an incubator, in combination with the incubator casing, a systemfor circulating water therethrough,,means for regulating the flow ofsaid water including a valve in said system, said valve including aspherical portion for engagement with the valve seat and a conicalextension projecting through the valve port, a lever for operating saidvalve, a sleeve projecting through said casing, a thermostat adjustablymounted on the inner end thereof having operative connections with saidlever passing through said sleeve, an adjustable fulcrum member for saidlever clamped in adjusted position bysaid sleeve, a heater for saidwater, controlling means therefor, and

a second thermostat located in said circulating system operativelyconnected to said controlling means.

6. In an incubator, in combination with an incubator casing, a systemfor circulating water therethrough, a heater for said water, controllingmeans therefor, a thermostat in said system operatively connected tosaid controlling means, and means for regulating the temperature withinsaid. casing including a valve in said system, a valve stem therefor, alever engaging said valve stem, a fulcrum for said lever, an adjustableweight on said lever between said fulcrum and valve stem, a sleeveprojecting through said casing, a thermostat mounted thereon within saidcasing, a member operatively connecting said thermostat and leverpassing through said sleeve, and one or more adjustable weights on saidlever on the opposite side of said fulcrum from said valve stem and soositioned that the center of gravity of said lever and weights is abovesaid fulcrum.

.7. In an incubator, in combination with the incubator casing, means forregulating the temperature within said casing including a valve and alever for operating the same, a sleeve projecting through the casingwall, means clam ing said sleeve to said wall, an adjustable ulcrumplate for said lever clamped in osition by said sleeve, a thermostatadjusta ly mounted on the inner end of said sleeve, and a rod projectingfreely through said sleeve and contacting the movable wall of saidthermostat and said lever.

8. In an incubator, a circulating system, a valve controlling the flowof heating medium therethrough, a lever for operating said valve, athermostat within said incubator and operatively connected to saidlever, said lever carrying one or more adjustable weights so positionedthat the center of gravity of said lever and weights is above saidfulcrum.

In testimony whereof I have signed this specification.

JEAN v. GIESLER.

